Final answer:
The connective tissue layer that separates a muscle into small bundles called fasicles is known as fascia. It allows the nervous system to trigger specific movements of a muscle by activating a subset of muscle fibers within a fascicle.
Step-by-step explanation:
The connective tissue layer that separates a muscle into small bundles called fascicles is known as fascia. Inside each skeletal muscle, muscle fibers are organized into individual fascicles by the middle layer of connective tissue called the perimysium. The fascial organization allows the nervous system to trigger specific movements of a muscle by activating a subset of muscle fibers within a fascicle.